Method of drying thread or the like



Nov. 24, 1942. s FRYER ETAL 2,302,908

METHOD OF DRYING THREAD OR THE LIKE Filed Sept. 28, 1939 4 Sheets- Sheet1 W\ U q Summers Z6 ou|s s. FRYER EMERSON B. HELM KENNETH M. McLELLAN BYiztomcg Nov. 24, 1942- s. FRYER ET-AL 2,302,908

I METHOD DRYING THREAD OR THE LIKE Filed Sept. 28, 1933 4 Sheets-Sheet2- Jnoenfors LOUIS S. FRYER EMERSON B- HELM AND KENNETH M. McLELLAN Nov.24, 1942. L, FRY R HAL 2,302,908

METHOD OF DRYING THREAD OR THE LIKE Filed Sept. 28, 1939 4 Sheets-Sheet3 3 nuemors LOUIS S. FRYER EMERSON B. HELM AND BY KEZNETH M- McLELLANfix i ittrney L. s. FRYER ETAL METHOD OF DRYING THREAD OR THE LIKE Nov.24, 1942.

Filed Sept. 28, 1939 4 Sheets-Sheet 4 m D m Q m m Q a a a a a \\m and sw m. .Q. MHM. m Q mvR Q FQMM... 1 v 1 1 I, I. D N a 6? w 1 i UEN/ 8 Q wmIN a W v "a K R R R 5 m x NR x Nu m. N D R 9 ML 4 Q Q N R SE mum Na .QRQQR 8%. w #8 5w n i d w m 6 Q l HQ J mm 3v m? R. MM QM gm 7 QR 6% m 6R.8h Q mm 8% M 6 m Patented av. 24, 1942 STATES P and Kenneth M. McLellan, Lakewood, Ohio,

assignors to Industrial Rayon Corporation, Cleveland, Ohio, acorporation of Delaware Application September 28, 1939, Serial No.296,930'

. 4' Claims.

This invention relates to methods which may be used in manufacturingand/or processing strip material such as threador the like (hereinafterreferred to as thread). More particularly, the invention is directed tomethods which may be employed advantageously in the manufacture and/orprocessing of textile thread to control certain of the physical andphysico-chemical properties thereof; e. g., shrinkage, dyeing and othercharacteristics. The invention is especially useful in the manufactureby a continuous process of multiple filament artificial silk thread; i.e., rayon.

The use to which a completed commercial textile thread is ultimately tobe put is determinative of the nature of the physical andphysicochemical properties imparted to the thread. Such properties areinfluenced largely by the type of treatment employed in the processingof the thread.- For example, a textile thread, to be commerciallyacceptable for general use in the weaving industry, must almost alwayspossess a low residual shrinkage capacity. The term residual shrinkagecapacity, as used hereinafter, is defined as the amount by which a dry,finished thread will shrink, if unrestrained in any manner, upon beingrewet and redried.

Commercial textile thread employed'in weaving, particularly for use as aweft thread, should be of such low residual shrinkage capacity as topreclude the possibility that the fabric woven therefrom will shrink bymore than a very small amount, if at all, during the subsequentfinishing operations. The finishing operations ordinarily consist of wne. dyeing, etc., after which the fabric is usually dried in rigidtentering frames which hold the fabric to the desired finished width. Ifthe residual shrinkage capacity of the thread from which the fabric iswoven exceeds very low limits, the tendency of the fabric to shrinkstresses the thread, causing barr effects to develop in the fabric andin some cases causing the fabric to 'be torn from the tenteringframes.In either case, the commercial value of the fabric is seriouslyimpaired.

Furthermore, weaving thread should have throughout its length a uniform,and preferably high; afllnity for dyestuffs. Uniformity of dye affinityis important inasmuch as a woven fabric formed of thread which does notpossess the desired uniformity usually embodies defects of the typeknown to the trade as shiners or dye barre which deleteriously afiectthe commercial acceptability of the fabric. produce a thread having highdye affinity be- It is desirable to' sodium cellulose xanthate(viscose). Coagulation is brought about by extruding the solutionthrough a plurality of minute orifices into an. acid precipitating bath,an operation which gives rise to a delicate thread consisting of aplurality of filaments that, at least at this stage, are more or lessgelatinous in nature. Subsequent to coagulation, the thread isordinarily subjected before it is initially dried to suitable processingtreatments including washing, desulphurizing, etc. During theseoperations and in fact until such time as it is completely solidifiedand dried, the thread is usuallyconsidered to be in a gel state.

Great care must be exercised in processing thread while it-is in the gelstate inasmuch as its physico-chemical properties are markedly affectedby the nature of the processing treatments, as well as by the manner inwhich the treatments are administered to the thread. It has been found,for example, that the manner of drying the thread initially; i. e., fromthe gel state, determines to a large extent the final char acteristicsofthe finished thread, particularly its dyeing properties. This is equallytrue whether the thread ismanufactured by the so-called continuousprocess or according to the discontinuous methods of producaion bywhich, until recently, all viscose artificial silk thread was produced.

' Among other things, the tension imparted to the thread during itsdrying from the gel state affects the physico-chemical characteristicsof the thread. For example, if thread is dried in the spool package inwhich it is collected in the spool-spinning process, uneven dyeingproperties result. Such non-uniformity results from the fact thatshrinkage of the innermost layers of thread is prevented by the presenceof the spool, while the faster drying outer layers of thread areprevented from shrinking only by the slower drying intermediate layers.Different portions of the thread are differently stressed, resulting inwidely varying dyeaflinities. As a rule, such irre ularities renderspool-dried thread unfit for capacity taken to improve its uniformity.

To overcome these difficulties, it has been. the

usual practice in the manufacture of weaving thread by discontinuousprocesses .to dry the thread in the form of a skein containing severalthousand yards of thread; The skeins are usually formed by unwinding thethread from the package in which it was collected and rewinding it intoskein form, in which state the thread can be supported so that it hangssubstantially freeof tension during drying. The thread can thereforeshrink freely, wherefore it has a low residual capacity to shrink;however, even such skein-dried thread does not have absolute uniformity,this for the ireason that the outer windings ofthe thread in the skeintend to dry more rapidly than the intermediate windings and thereforesubject the thread to tension differences which affect its dye aflinity.

On the whole, the discontinuous production of viscose weaving thread isunsatisfactory because of the high cost of production, the waste of thethread due to injuries resulting from repeated handling, and the longperiods of time required in processing. The completed product does notpossess the desired uniformity of shrinkage, dye:-

ing and other characteristics; so that in general it is not capable ofmeasuring up to the extremely hi h standard of-quality which. isdesired. For such reasons, to, produce viscose. weaving threadcommerciall 'by'a continuous. process wherein 'such disadvantages 'areeliminated has long been recognized as a desideratum. However, thecontinuous production; of viscose artificial silk thread involves otherproblems not present in discontinuous methods of 'production. Suchproblems arise primarily ,out of the fact However, the presentinvention, in addition to obviating the numerous disadvantages of thediscontinuous process, gives rise to a thread which is eminentlysuitable for weaving, which is of a particularly high degree ofuniformity of physical and physico-chemical characteristics, and whichis characterized by a permanently low residual shrinkage capacity. Theinvention makes these results possible by repeatedly drying andrewetting the thread in a continuous process while permitting it toshrink under predetermined conv ditions, all as more fully explainedhereinafter. For convenience the invention will be described as appliedto the manufacture of multiple filament viscose artificial silk threadon apparatus operating on the principle of thatshown, de-- scribed andclaimed in Knebusch et. al. Patent v In the drawings, Figure 1represents a sectional elevation of one form of apparatus in which theinvention is embodied. Figure 2, whichrepresents a portion of theapparatus of Figure l on an enlarged scale, shows the means forrepeatedly wetting and drying the thread according to the invention.Figure 3 illustrates on the same enlarged scale a similar portion ofmodified apparatus likewise embodying the invention. Figure 4 is an endelevation of one form of thread- -advancing reel employed to dry thethread. Figure 5 represents a sectional elevation of said reel from line55 of Figure 4.- Figure 6 is a sectional elevation of another type ofthreadthat in the continuous process thread in the finished state isproduced from liquid viscose in a very small fraction of the timerequired in dis.- continuous p.ocesses. Whereas in discontinuous;processes thousands of yards of thread wound' in a package are subjectedto for many hours or even days, process not more than a few yards ofthread are subjected to a given set of processing conditionssimultaneously. In particular, the shortness of the time available forthe initial drying of the thread from the gel state is a factor causingdifficulties in the manufacture of thread by a continuous process.

,In the continuous process of manufacture, it has been found that therapid initial drying of .the thread from the gel state does not giverise to a permanently low shrinkage capacity, this even if the thread ispermitted to shrink during such drying'operation. The residual shrinkageof thread dried under such conditions is often .so high that the threadis not well adapted to weaving on looms producing fabrics of widthsapproximating the intended finished width of the fabric. This difiicultyis probably related to the fact that in the continuous process thethread is dried in only a few seconds or, at the most, a minute or two.Such difliculties are not found in the manufacture of weavingifim' eadby discontinuous processes.

It has therefore been continuous process constitutes a very greatimprovementoverthe discontinuous processes iii thought that, while the};

" cose from a spinneret 2 disposed in a coagulating.

processingconditions in the continuous advancing reel employed to drythreadafter intermediate rewetting.

- Figure 1 shows a complete machine for continuously manufacturingmultiple filament viscose artificial silk thread of low residualshrinkage capacity in accordance with the teachings of thepresentinvention. Said apparatus, a portion of which is shown in greater detailin Figure 2, is adapted to produce a large number of threadssimultaneously, each by the extrusion of visbath 3 contained in trough4. Each thread 1 passes to a thread-advancing reel 5, the same being thefirst of a concatenate series of threadadvancingreels designated 5 to H,inclusive.

. In the apparatus of Figures 1 and 2, the threadadvancing reels 5 to14, inclusive, take the form of reels of cantilever constructionoperating on the' principle of that described in said Patent -2,225,643.Each of the reels 5 to [4, inclusive,

advances the thread toward the unsupported end 7 thereof in a largenumber of closely spaced, generally'h'elical turns. Onisaid reelssuitable liquid processing operations such as washing, desul phurizing,etc., are performed on the thread,

, after which the thread is dried. From the last reel M, the threadpasses to suitable collecting apparatus, such as the cap-twister|5,'Whi0h collects the finished thread ill package form.

. In said apparatus, each thread-producing unit comprises a'spinneret, adescending series of reels 5 to, inclusive, and an associatedcap-twister.

The reels in each descending series are disposed in stepped arrangementwith the unsupported or discharge end of each preceding reel in oppositerelation. to the supported or receiving end of the succeeding reel, theunsupported ends of all reels extending inthe same direction. Aplurality of such thread-producing units is disposed on each side of theapparatus; so that the apparatus as a whole has two operating faces, oneon each side thereof. Corresponding parts of all units on each s de ofthe apparatus are therefore in correspondmg positions a wise thereof.

The use to which the finished thread is to be put is largelydeterminative of the nature of the processing treatments and the mannerof administering the treatments to each of the threads I. In theillustrated apparatus, the thread I is drawn upward by reel 5, on whicha relatively long length of the thread is continuously but temporarilystored in order to provide suificient time for the thread to achieve thedesired degree of coagulation before it is subjected to subsequentprocessing treatments. The thread then passes from the unsupported endof reel to the supported end of succeeding reel 6.

On reel 8, the thread may, if desired, be subjected to the action of anadditional coagulating liquid. Wash water may next be applied to thethread on reel I, after which any free sulphur which may be produced inthe thread as a result of the regeneration process may be removed by theapplication to the thread on reel 3 of a suitable desulphurizing liquid.The thread may be washed again on reel 9 to free it of thedesulphurizing medium and, if desired, may be bleached on reel III. Thethread I then passes to reel II on which it may again be washed.

In the embodiment of the invention illustrated in Figures 1 and 2, theliquid to the action of which the thread is subjected on reel 6 issupplied from a reagent distributor I'I communicating with a supply pipeI8 which extends 1on7 gitudinally of the apparatus on each side thereof.Similarly, the liquid supplied to each of the succeeding reels 'I to II,inclusive, is applied to the thread from a reagent distributor I'Icommunicating with a conduit I9 which extends longitudinally of themachine, being formed integrally with the lower portion of collectingtrough 2I disposed beneath the preceding reel. Collecting troughs M aredisposed beneath all the reels. from which "liquid drips from thethread, such liquid being recirculated and reused.

The various processing liquids are applied to the thread on reels 6 to II, inclusive, at the unsupported end of each reel in such manner as toform a travelling film of liquid extending uninterruptedly around theentire thread-bearing periphery of the reel. In the illustrated appa-.ratus, the reels are inclined to the horizontal in order that such filmof liquid may travel along each reel from the-unsupported end toward thesupported end thereof, thus providing a countercurrent flow of liquidwhich more effectively processes the thread. Although these conditions'do not occur on reels I2 and I3, it is con-. venient from aconstructional standpoint to tilt them also. According to the presentinvention, after the aforementioned treatments have been performed, thethread is dried on reels-I2, I3 and I4, as explained hereinafter.

After threadI-has been completely processed, it is passed from the lastreel I4 to cap-twister 16 by means of which it is twisted and collected.The collecting apparatus comprises a continuous belt 22, driven byrotating drum 23, which belt, guided by suitable pulleys, passes aroundthe whirls 24 of cap-twisters IS on opposite sides of the apparatus,thus rotating the bobbins 25 and claimed in Bergmann et a1. Patent2,203,665.

According to the invention, thread which has been formed as abovedescribed but which is still in the gel state is subjected to repeateddrying with intermediate rewetting on a plurality of reels underconditions permitting shrinkage of the thread in the course of at leastone drying operation. During the time that the various liquid processingtreatments are being administered to the thread on the reels prior toreel I2, the thread is always in the gel state. On reel I2, however, thethread is subjected to its initial drying operation, being dried bymeans of heat applied 'to the reel from the interior thereof. Afterbeing dried on reel I2, it is rewet, stored under conditions such thatexcess liquid carried by the thread may drip therefrom on reel I3, anddried once again on reel I l.

While various modifications thereof may be employed, the apparatus shownin Figure 2 has been found to be extremely satisfactory for thesepurposes.

In said apparatus, each of the drying reels I2 and It is formed ofmetal, being heated internally thereof by the means hereinafterdescribed. The thread passing'from reel II to reel I2 is substantiallycompletely dried on reel I2, but just before it leaves said reel at theunsupported end thereof it is subjected to the action of a small streamof an aqueous rewetting liquid supplied from reagent distributor 29.

The liquid thus applied to the reel is not sufiicient in amount tospread over the reel but only to wet the last few turns of thread on thereel; however, the amount of liquid is suflicient to wet the threadthoroughly. The wet thread then passes to the reel I3 which, in theembodiment of the invention illustrated in Figure 2, constitutes a dripreel.

No processing medium is applied to the thread on reel I3; instead, theliquid applied to the thread just before it leaves reel I2 is permittedto drip therefrom. In view of the length of thread which is stored inthis manner, drops of excess moisture carried by diflferen't portions ofY the thread which would otherwise tend to immounted on the whirls ofsuch cap-twisters.

' Such cap-twisting apparatus forms no part of v the present invention,but is shown, described pair the uniformity of the subsequent dryingoperation may be removed by simply permitting them to drip from thethread. A mild evaporative action also takes place due to the exposureof the thread to the air. Consequently, when the thread reaches thedischarge end of reel I3, all portions of the thread have the same orsubstantially the same moisture content.

The thread passing to reel I4, having a substantially uniform moisturecontent, may be uniformly dried on reel I4 provided that uniform dryingconditions are applied to the thread. To aid in maintaining uniformityof drying conditions, an enclosure 30 is provided surrounding each reelI4. Said enclosure comprises a stationary portion 3| and a hingedclosure por-' tion 32. Slots 33 and 34 are provided at the junctions ofthe hinged and stationary portions to permit the thread I to enter andleave said chamber in passing to and from reel I4. If desired, a similarenclosure may, of course, be pro-. vided for reel I2.

Among other things, the invention contemplates that shrinkage of thethread shall be permitted to take place as hereinafter described for thepurpose, for example, of imparting the desired low residual shrinkagecapacity .to the thread.

During the initial drying of the thread-on reel I! a certain amount ofshrinkage tends to occur in the thread. It has been found advantrolledshrinkage of the thread in this manner,

the dye aflinity of the thread is favorably influenced, the threaddyeing somewhat darker than otherwise would be the case.

It has been found that a slight elongation of the thread occurs when itis rewet. In the apparatus illustrated, this is compensated for byrotating the reel i3, to which the thread passes after it leaves reel H,at a peripheral speed sufiiciently greater than that of the dischargeend of reel i2. With that in mind, reels i2 and iii are rotated at thesame angular speeds, but the diameter of reel [3 at its supported end isslightly larger than that of reel l2 at its un-' supported end.Preferably, the ratio of the diameters is such that neither tension norslack is developed in the thread passing from reel i2 to-reel IS. Thesame eifect may, of couse, be

obtained with reels of equal diameters by. imposing a suitabledifference on the angular velocities of the reels.

vNo appreciable shrinkage of the thread occurs while it is stored onreel l3; conrequently, reel i3 may be formed with no variation in thediameter thereof.

Re'el I4, however, is preferably provided with a contour of a charactersuch that as the thread dries it may shrink freely. This is accomplishedby forming the periphery of the reel so that it conforms closely to theshape of the diminishing helix which thethread tends to develop as itshrinks. It is known, for example, that the thread does" not begin toshrink as soon as it comes into contact with reel I4, wherefore the reelmay, as shown, he made substantially cylindrical for a considerableportion thereof.

During this portion of the drying operation, external moisture only isbeing removed from 'the thread, the removal of which does not result inshrinkage of the thread.

Thereafter the internal moisture is removed,

' which results in marked shrinkage of the thread;

accordingly, the reel I4 is tapered over the intermediate portionthereof. The minimum diameter of the tapered portion of the reel is.such that suf cientshrinkage is permitted by the'time the thread reachesthe end of the tapered portion to impart to the thread the desired lowresidual shrinkage capacity. If desired, the tapered portion of the reelmay be so formed that the dried thread has virtually no residualshrinkage capacity whatsoever.

1 The final portion of the reel, which is of substantially cylindricalform, serves among other things. to insure substantially equal drying ofthe thread throughout its length. For example. portions of the threadwhich have not been as completely dried as other portions are enabled tocomplete their drying on such cylindrical'portion before they leave thereel. In general, it is desirable that the thread leaving this portionof the reel have a final moisture content in the neighborhood of 10%,more particularly since a moisture content of this order, especially atelevated temperatures, greatly facilitates twisting the thread. I

Reel H, as also reel I2, may advantageously have a contour conforminggenerally to that shown and described in Kline et al. Patent 2,203,686.The reel of said patent is so designed that the diameter of the reel ineffect diminishes in the direction of travel of the thread more rapidlythan the diameters of the thread turns tend to diminish as a result ofshrinkage of the thread. Consequently, substantially un restrainedshrinkage of the thread is possible in spite of unintentional variationswhich sometimes occur in the intensity of the drying conditions to whichthe thread is subjected on the reel.

The apparatus as a whole may be so designed that little, if any, tensionexists in the thread during the various drying, rewetting and redryingoperations, such slight tension as happens to be present beingsubstantially constant. This may be accomplished by relating theperipheral speeds of the various reels so that although slack due toelongation is taken up, no stretch is imparted to the thread. However,the amount of tension to which the thread is subjected and the amount ofshrinkage permitted in the thread during the first drying operation; 1.e., while it is being dried on' reel H, has little efiect upon' 'theresidual shrinkage capacity of the thread.

The features thus far described form the subject matter of Kline et al.Patent 2,286,213.

The present invention includes a further feature which is'extremelyuseful in producing low residual shrinkage capacities in thread which isbeing dried continuously; namely, maintaining the thread forasubstantial period of time at high temperatures under conditions ofhigh moisture content. By such means, what may be called a cookingeffect is imparted to the thread. This step of saturating the threadwith liquid while at a high temperature apparently plays.

an important part in the re-orientation of the micellar structure of thethread necessary to obtain substantially complete shrinkage thereof atthe high drying speeds employed in the con-' tinuous processing ofthread. Best results are obtained if the thread is subjected to acooking operation immediately after the initial drying of the thread,preferably before the thread has had time to cool aPDIeciably.

In the embodiment of the invention illustrated in Figures 1 and 2, apronounced cooking effect is produced at the unsupported end of reel l2:at that point,.an aqueous rewetting liquid is applied to the threadwhile the threadis still I at the relatively high temperature of thereel.

To aid in thec'ooking effect, a higher temperature is employed'on reell2 than on reel ll: indeed, it has been found desirable to maintain thetemperature- 0f reel l2 considerably above the boiling point of therewetti-ng liquid; 1. e.,

at a temperature in excess of 100 C. It has also been found desirable tomaintain the temperature on reel H below the boiling point of therewetting liquid, since this permits a more nearly complete shrinkage ofthe thread. The rewetting liquid may be either cold or-ho x but,

in accordance with the practicof this in '1- tion,- is preferablyemployed after being 1. st

heated to a temperature approaching the point of water.

boiling While the embodiment of the invention, shown in Figures 1 and 2is preferred,apparatus embodying'the inventionin modified form may alsobe employed. Thus in Figure 3, which repre sents abortion of acontinuous processing apparatus generally similar to that shown inFigure 2, the rewetting liquid is not applied to the thread on the reel2, but is applied to the thread after it leaves said reel. Morespecifically, the rewetting liquid is applied to' the first few turns ofthread on reel 3. It is applied by means of a reagent distributor 29asupplied fram 'a conduit I9 forming part of the trough 24 disposed belowthe preceding reel. The remainder of reel l3, on which portion no liquidof any kind is applied to the thread, serves as a drip stage foreequalizing the moisture content of the thread, precisely as has beenexplained above in connection with reel l3 of Figure 2.

The rewetting liquid applied to the thread on reel i3 may be at roomtemperature but preferably is heated, since this produces a cookingeffect generally similar to that produced at the unsupported end of reell2 in the embodiment of the invention shown in Figure 2. However,somewhat better results are obtained when the rewetting liquid isapplied to the thread while the thread itself is heated. In theembodiment of Figure 3, the reel I2 is shown as having no taper tocompensate for the tendency of the thread to shrink, each reel memberbeing substantially cylindrical in form. As has been ex- A bolt 45,holding a washer 46 against the outer sealing member 43 at theunsupported end of the reel, is threaded into a plug 41 welded in theunsupported end of hollow shaft 31. A washer 48, -disposed on shaft 31as by means of the snap ring 49 shown, bears against the outer sealingmember 53 at the rear of the reel member 35, serving thereby to locatereel member 35 endwise on the shaft. As bolt is tightened, it forces thewedge-shaped members 43 together at both ends of the reel member 35,thus effectively sealing the reel member 35. The tight fits at thesepoints on shaft 31 also provide the necessary driving engagement ofmember 35 with mounted concentrically upon a rotatably mountplainedabove, tapering reel l2 has relatively little eifect on the residualshrinkage capacity of the thread. In all other respects, the em-=bodiment of the invention shown in Figure 3 is similar to that shown inFigure 2.

As is apparent from Figures 4 to 6, inclusive, each of reels i2 and Itcomprises two wholly rigid reel members, each such reel member being ofsubstantially circular cross section. Each reel member has a peripherymade up of a plurality of longitudinally extending bar members which areinterleaved with the bar members of the other reel-member. The two reelmembers rotate about axes displaced from and inclined to each other insuch manner,v as to advance the thread in a large number of closelyspaced, generally helical turns from 'the supported end to theunsupported end thereof.

Reel i2, as canhe seen from Figures 4 and 5, comprises two rigid reelmembers 35 and 36 each of which is substantially circular in cross sec-.tion. Member 35, which may be termed the concentric member, is mountedconcentrically upon and for rotation with hollow drive shaft 31. Itsperiphery is made up of a plurality of spaced, longitudinally extendingbar members 38. Member 36, which may be termed the eccentric member, isrotatably mounted with its axis inclined to but in a plane slightlyoffset from the axis of reel member 35. Its periphery includes aplurality of spaced, longitudinally extending bar members 39 alternatelydisposed with respect to bar members 38 of concentric reel member 35;

Concentric member 35 may be formed as shown with the bar members 38integral with hollow body portion 58. In the illustrated reel, front andrear members 4| and 42, respectively, form fluid-tight junctions withhollow body portion 30. Said members also surround hollow shaft 31.Cooperating annular sealing members 43 disposed in recesses Min members4| and 42, which sealing members are wedge-shaped in cross section,operate to prevent the escape of fiuid past the shaft from the interiorof reel member 35.

bearings 6! and 62.

ed supporting member 5|, as by bolts 52. Rigid cagelike member 50.comprises the aforementioned bar members 39 which are fixed at theirsupported ends to an external annular supporting rib 53 by means ofwhich the cagelike member is mounted on said supporting member 5|. Anannular reinforcing member 58 is fixed to the bar members 39 attheirunsupiaorted'ends. Supporting member 5| is mounted on frame member55 for rotation about an axis disposed in the desired offset andinclined relationship with respect to the axis of rotation of concentric member 35.

Supporting member 5| is formed so that pro jecting boss 56 of framemember 55, on which said member 5| is rotatably mounted by means ofspaced antifriction bearings 51, is disposed within the reel proper. Tothis end, the rear closure member 42 of the concentric member 35 is sopositioned that the boss 56 can be disposed within the reel member 35.The purpose of this arrangement is to provide a construction such that,although the fiuid supply and removal means are associated with saidframe member 55, the overall length of the reel and its supportingmember is only slightly, if at all, greater than one of the liquidprocessing reels 6 to H, inclusive. Thus, a reel of this type can besubstituted, if desired, for any one of the liquid processing reels.

Reel i2 is similar to the liquid processing reels in that its framemember 55 is provided with a flanged portion 58 adapted to be held byset screws 60 in a cup 59 fixed to frame 16 of the apparatus (Figure 2);

- Drive shaft 31, on which concentric member 35' is rigidly mounted,passes through frame member 55, being journalled therein by spaced Inthe reel illustrated in Figures 4 and 5, an annular, internally toothedmember 63 fixed to the inner wall of hollow body portion 40 meshes withexternal teeth 64 formed on supporting member 5|, thus providing meansfor driving the eccentric member from the concentric member withoutcontact of the bar members of the reel members. The bar members, beingformed of a metal such as aluminum which is chosen for its high heatconductivity, would otherwise wear easily.

Bevel gear 65, fixed to the rear end -of shaft 31, meshes with bevelgear 66 mounted on vertically inclined drive shaft 61; similarly, eachof the other reels 6 to M, inclusive, is driven from drive shaft 61.

Reel I2 is heated by the circulation of a suitable heating fluid throughthe hollow body'portion 40 of concentric reel member 35. As isstationary memberv 12 against which bears a Suitable Member 36a, whichmay be termed the eccentric member, is rotatably mounted with its axisslightly offset from and inclined to that of mem-- ber 35a. Itsperiphery includes a plurality of spaced, longitudinally extending barmembers members 38a of reel member 35a.

rotatable bearing member 13 urged thereagainst by a spring 14, Spring 14is compressed between a flexible annular sealing member 15 seated onmember 13 and a support 16 rigidly fixed to the drive shaft 31, as by aset screw 11. The support 16 in compartment 68 serves both seals Ntherein, while the support I6 in compartment 69 serves a single seal.Said seals aid in locating. the drive shaft 37, and consequently thereel member 35,

endwise of the reel.

Compartment 6B is provided with an opening :18 through which heatingfluid is supplied from tube 19 connected to' frame member 55. The

heating fluid passes through a port 80 in the wall ofhollow drive shaft31, thence longitudinally of said drive shaft, and finally through port82 into the interior ofhollow body portion 40.- The heating fluid passesout of said hollow body porshaft 31'which opening communicates with aninterior tube 84 rigidly fixed in said drive shaft.

The plug 41 at the unsupported end of hollow drive shaft 31 serves toseparate the inner tube and the drive shaft and to prevent fluid frompassing directly from the.drive shaft to the .tube

,tion 40 through an opening 83 in hollow drive or vice versa. A similarplug 85 at the rear portion of said drive shaft 31 prevents the inter,-mixing of the entering and discharging fluid.

port 86 into the rear compartment 69, from which it passes out throughopening 81 to a discharge In the apparatus shown in Figure 2, supply,The fluid passes from said inner tube 84 through tube 19 is connectedto a supplyconduit 89 which extends lengthwise of the apparatus in such-manner as to permit it to serve a plurality of reels I? disposedlengthwise oft-he machine as a whole. Similarly, discharge tube 88communicates with a discharge conduit 90 which extends lengthwise of theapparatus to permit it to accommodate a plurality of reels l2.Regulating valves 92 may be provided, as shown, to control-the flow ofheating fluid through the reel l2. The heating.

fluid may be hot water, steam or. any other suitable fluid which may beheated .and circulated through the system. Other heating and circulatingmeans than that illustrated may of course be employed.

The reel member 35 and the bar members 38 thereof are thus directlyheated by the fluid circulated therethrough. The other reel member 36,and particularly the bar members 39 thereof,

are heated by radiation and conduction from concentric reel member 35.This arrangement is particularly efficient for drying thread, which isthe subject matter of Bergmann Patent 2,281,406. Reel I4 is similar inmany ways to reel t2 and operates in a generally similar manner. .Asappears from Figure 6, it comprises two wholly rigid reel members 35:;and 36a. Concentric member 35a, the periphery. of which is defined by aplurality of spaced, longitudinally extending bar Concentric member 35ais formed as shown with its bar members 38a integral with a hollow bodyportion 40a. Members Ma and 42a, forming fluid-tight junctions with saidbody portion 40a, not only close off the ends of said body portion butserve as means for mounting the reel member 351; on drive shaft 31a.Reel member 35a is held on drive shaft 310 against a collar 49a, fixedto-said drive shaft, by bolt 45a threaded into the end of said driveshaft. Packing 93, which is disposed in a recess 44a in member 42a, iscompressed against collar 49a in order to prevent the escape of heatingfluid from the interior of body portion 40a.

Eccentric reel member 36a is formed of a rigid cagelike member 500concentrically mounted upon a rotatable supporting member 5la by meansof bolts 52a. Rigid cagelike member a comprises the bar members 39a.fixed at their supported'ends to an external annular reinforcing rib53a, by means of which said cagelike member 50a is mounted on rotatablesupporting member 5Ia, 'and an annular reinforcing rib 54a fixed to thebar members 39a at their unsupported ends. Supporting member SM ismounted by means of spaced anti-frictionbearings 51a upon frame member5512 for rotation about an axis disposed in the desired offset andinclined relation with respect to the axis of rotation of concentricmember 35a. 5

An externally toothed member 6441 closure member 42a engages an annularinternally toothed member 6311 on supporting member 5|a, thus drivingeccentric reel member36a from concentricreel member 35a. 7

Drive shaft 31a is journalled in frame member- 55a by means of bearingGla disposed at the unsupported end of said frame member and by means ofantifriction bearing 62a supported in a cross member 94 fixed to thespaced, longitudinally extending members 95 forming part of frame member55a. It is positioned against andwise movement between collar 49a andcollar 96 hearing against the inner race of antifriction bearing 62a.Drive shaft 31a is rotated by means of a bevel'gear 65a mounted on saidshaft between the longitudinally extending members 95. Bevel gear 65ameshes with a corresponding gear 'on inclined drive shaft 61. vFrame'member 55a is provided with a flanged portion 58a adapted to fltclosely into and to be held in a cup member 5911' fixed to the frame ofthe apparatus, whereby reel II is demountably supported in theapparatus. I

The means for circulatin heating fluid through the reel is generallysimilar to that-above described. -A fitting '91 mounted on thelongitudinally extendi'ng'members of frame member 5511 is provided withtwo compartments 68a and 69a. The drive shaft 31a projects into theforward compartment 68a, while tube 84a, fixed in said hollow driveshaft 31a, extends into rear compartment 691:. 'Suitable plugs 41a-and95a are provided in said hollow drive shaft31a to support inner tube 84a.and prevent fluidfrom passing directly from hollow driveshaft 31a tomembers 38a, is mounted concentrically upon and for rotation with hollowdrive shaft 31a.

on rear Heating fluid is supplied to compartment 68a through opening 18aand passes through ports 81a into the space between the inner tub 84aand the inner surface of hollow drive shaft 311:.

The fluid passes out of said hollow drive shaftthrough ports 82a intothe interior of body por-,

tion 40a of concentric reel member 35a. After circulating through saidbody portion, the fluid passes through ports 83a into the interior ofinner tube 84a, whence it is discharged into the rear compartment 69a.The heating fluid passes out of said compartment through port 81a.

In the embodiment of the invention shown in Figure 2, heating fluid issupplied through conduit 89a which extends longitudinally of themachine. Tube 19a conducts the heating fluid from conduit 89a toentrance port 18a of reels l4. After the heating fluid has circulatedthrough the reel, it passes through a tube 88a connected to thedischarge port 81a to a discharge conduit 90a extending longitudinallyof the apparatus. The heating fluid for reels l4 may comprise anysuitable medium such as hot water, steam or other suitable fluid.

Using the methods and apparatus of the invention, it is possible toproduce by a continuous process viscose artificial silk thread having ahighly uniform residual shrinkage capacity in the neighborhood of oneper cent. The precise value in a given case depends upon variousfactors, but' will usually be found to be within the range between threequarters and one and one quarter per cent. All other physical andphyslcochemical characteristics are likewise extremely uniform. Theexample which follows is illustrative of the practice of the invention,the apparatus employed being that illustrated in Figures 1 and 2.

Viscose artificial silk thread of 150 denier, 40 filaments, is deliveredat a speed of 68 meters per minute to reel 12, which is preferably madeof aluminum. Still in the gel state when it ,is passed to the reel, thethread has a moisture content of approximately 400%. The thread is atordinary room temperatures before it is taken up by the reel, which isheated to at least 115 C.; so that it is subjected on the reel to asudden rise in temperature of approximately 90 C.

At the high temperature to which the reel is heated, the moisture is'rapidly driven from the thread. The thread advances several turns beforeit begins to shrink; accordingly, the reel is of substantiallycylindrical configuration for about 1.5" lengthwise of itsthread-bearing periphery, measuring from the supported end of the reel.From this portion, where the reel is of 5" diameter, the reel is taperedto a diameter of approximately 4.9", this in order to allow forshrinkageof the thread during the phase of the drying operation during which theinternal moisture is removed from the thread.

The last few turns of thread at the unsupported end of the reel; i. e.,for a distance of about A lengthwise of the periphery of the reel, arerewet with an aqueous rewetting liquid after the thread has been driedbut while it is still at an elevated temperature. The rewetting ispreferably done by applying the liquid to the thread at the rate ofabout 30 cc. per minute, the rate being determined by the amount ofmoisture fabric.

which can be reabsorbed by the thread. The thread will ordinarily absorbthe rewetting liquid only until it attains a moisture content slightlyin excess of 200%.

The application of the rewetting liquid results in elongation of thethread, wherefore reel I3 is 5' in diameter at the portion on which thethread starts. It revolves at the same angular velocity as the precedingreel, the difference between the 5" diameter of reel l3 and the 4.9"diameter of reel 12 being suflicient to allow the thread to pass fromreel i2 to reel I 3 without slackness or tension. Reel [3, being formedof hard rubber or other plastic material, is not heated, but is of thesame type as reels 6 to II, inclusive. The reel is of substantiallycylindrical configuration throughout its length, having a thread-bearingperiphery in the neighborhood of 5" long.

As it leaves reel I3, the thread has a highly uniform moisture contentof approximately 200%, based on the weight of the thread.

Reel [4, on which the flnal drying of the thread is accomplished, isordinarily designed to be heated to a temperature not greater than 0.,depending upon the nature of the thread being dried. In the instantexample, it is heated to about 78 C. An initial length of 1.5" of theperiphery of the reel nearest the supported end is substantiallycylindrical. The next 3.5" of the length of the reel is tapered to allowfor shrinkage of the thread in the absence of substantial tension. Thelast 1.5" is substantially cylindrical to allow for complete drying ofthe thread after completion of the shrinkage. reel I4 is of aluminum.

Under these conditions, no loops form in the thread during the seconddrying operation, this even though the thread permitted to shrinkfreely. The thread is characterized by straight filaments of highlyuniformcharacteristics. By contrast, thread which is dried only once,even with substantially unrestrained shrinkage, is

characterized byloops in its filaments which not only impair theappearance of the thread but also introduce difiicuities in forming thethread into This fact, together with the fact that on rewetting thethread absorbs at most considerably less than its original moisturecontent; e. g., in the neighborhood of one-half of its original moisturecontent, indicates that a change in the structure of the thread takesplace in the course of the first drying operation.

Both the methods and forms of apparatus above described as embodying theinvention are susceptible of various modifications without departingfrom the spirit of the present invention. For example, more dryingoperations, with intermediate rewetting, may be employed than thosespecifically disclosed and other means for and methods of rewetting thanthose illustrated may be used. Either-as disclosed or as modified, theillustrated methods and forms of apparatus may be employed for otheruses; for example, the drying of materials other than textile thread perse. The term thread" in the appended claims is intended to includesimilar materials capable of being operated on and handled according tothe present invention.

It is intended that the patent shall cover, by suitable expression inthe appended claims, what ever features of patentable novelty reside inthe invention.

What is claimed is:

1. The method of continuously drying wet mul- Like reel l2,

tiple filament viscose artificial silk thread comprising thesuccessively performed steps of applying heat to the thread whilecontinuously but temporarily storing it in extended form in a series ofgenerally helical turns, the amount of heat applied to the thread beingsuffici'ent to dry it substantially completely; continuously rewett-ingthe thread with an aqueous liquid heated to a temperature near theboiling point of water, the thread being in extended form at the timethe 11) 'essing medium of any kind,,the period of storage being longenough to permit excess liquid carried by the thread to drip therefrom;and, while continuously but temporarily storing the thread in extendedform in a series of generally-helical turns at least some of which areof progressively decreasing diameter-{again applying heat to the threadinan amount sufilcient to dry it substantially completely. j

2. A- method as in claim 1 in which the rewetting liquid is-applied tothe dried thread before it has had an opportunity to cool appreciably.

3. A method as in claim 1 in whichthe first drying operation is carriedout at a temperature above the boiling point of the rewetting liquid. 4.A method'as in claim 1 in which the'second drying operation is carriedoutat a. temperature below the boiling point of the rewetting liquid.

' LOUIS S. FRYER.

EMERSON B. HELM. KENNETH M. McLELLAN..

QCERTI F ICATE OF comcwiom "'Novenber 2J4, 1%2, Louis s. FRYER, "ET AL.It '1s hereby ear-titled e rz pr eppear s-in the. pz iptedaficific'atiofi of the abovenmnb ered 'pzitent if equiring cdr recfiionasfollows; Page 2,1 sec- LeiEt QPafien t shpugld' be read with thf lscoi'recti'on' therein th at -the same may confionrto the record 91 the.ease in the Patent Office;

Signed and sealed this 29th da of December, D. 19%2.

v Henry Van-Ar'sdale (Seal) Acfiing- -c o mmiesioner ef- Patents.

